The Barbara Davis Center has two conjoint animal facilities. The first, opened in 1983, consists of a 700 sq. foot. area consisting of seven animal rooms each approximately 8 x 8. In addition this facility contains a cage storage room and a cage wash room with a better built cabinet cage washer. In April of 1987, with the addition of three new laboratories, the laboratory adjacent to the animal quarters was rennovated into a new animal surgery facility. This facility consists of a storage area and three additional animal rooms 6x14 in size. In addition this facility has bench space of 4 investigators. We intend to perform all surgical manipulations in this area and house the animals in the rooms within the surgery area. This will allow for the "old" facility to become primarily a breeding facility. Each unit has a separate attendant. Many Truelove, the present animal room attendant, will continue to be responsible for the older facility. She will continue to be supervised by Dr. Bellgrau Reginald Polk is presently being trained to be the attendant for the new facility. He will be supervised by Dr. Georgiou. When both areas become fully operational a student worker will likely be hired to assist in daily maintainance chores including cage washing and changing. This will become especially important as Mr. Polk or his replacement is trained as an assistant for general laboratory surgical procedures. With two separate attendants it should be possible to prevent cross contamination between surgically manipulated and immunologically compromised animals housed in the animal surgery facility and breeding stock in the old colony. These facilities are satellites of the University of Colorado Animal Resource Center (ARC) and are accredited by AAALAC. Although operated entirely by funds provided by the Barbara Davis Center the unit is periodically inspected by Dr. James Stevens who is the director of the ARC. It is Dr. Stevens who ensures that the Davis facility always meets or exceeds AAALAC requirements. All investigators must have approval of the University Animal Care and Use Committee to perform their experimental manipulations.